One of the most intensely discussed questions about Japan’s anti-virus strategy is why, despite having growing capacity, the authorities carry out so few tests. A meeting this morning with a senior official of the ruling Liberal Democratic Party offers a answer to the mystery.

The official answer is that Japan chooses to test people who are at particular risk or showing symptoms (not just people who are worried) and then aggressively isolates “cluster” infections when they occur.

Still, WHO advice is to “test, test, test”. What harm would there be in using more of the daily capacity of 9000 tests (at the moment there are usually around 1500 tests carried out, lower than most comparable countries)?

The answer is not medical, epidemiological or political (covering up a “hidden epidemic”) but bureaucratic. Because of the status of Covid-19 in the official hierarchy of diseases, anyone found to have it must go to hospital.

No matter your state of health - whether you just have the sniffles, or no symptoms at all - if the test is positive into hospital you go.

Consider what would happen then if Japan did carry out mass, “drive-in” type testing such as South Korea did. Tens of thousands of mild and asymptomatic infections would be be revealed - and each one of them would by law have to be quarantined in a hospital bed.

Other countries worry about their health care systems being overwhelmed by a surge in pneumonia cases in ICUs. Japan would be overwhelmed by a surge in people who have nothing wrong with them. No surprise at all then that they would want to test as few as possible.

It is, of course, an absurd example of the tail wagging the dog that pandemic strategy should be determined by an excessive bureaucratic rule (that’s me talking, by the way, not the senior LDP official).

The rules are going to be changed soon, lapparently - this is something that will happen within local government rather than at the national level. After that, my source expects that rates of testing will quickly increase...